How to use NetworkReachabilityManager in Alamofire

问题:

I want functionality similar to AFNetworking in Objective-C with Alamofire NetworkReachabilityManager in Swift:

//Reachability detection
[[AFNetworkReachabilityManager sharedManager] startMonitoring];
[[AFNetworkReachabilityManager sharedManager] setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
    switch (status) {
        case AFNetworkReachabilityStatusReachableViaWWAN: {
            [self LoadNoInternetView:NO];
            break;
        }
        case AFNetworkReachabilityStatusReachableViaWiFi: {
            [self LoadNoInternetView:NO];
            break;
        }
        case AFNetworkReachabilityStatusNotReachable: {
            break;
        }
        default: {
            break;
        }
    }
}];

I am currently using the listener to know the status changes with network

let net = NetworkReachabilityManager()
net?.startListening()

Can someone describe how to support those use cases?

回答1:

NetworkManager Class

class NetworkManager {

//shared instance
static let shared = NetworkManager()

let reachabilityManager = Alamofire.NetworkReachabilityManager(host: "www.google.com")

func startNetworkReachabilityObserver() {

    reachabilityManager?.listener = { status in
        switch status {

            case .notReachable:
                print("The network is not reachable")

            case .unknown :
                print("It is unknown whether the network is reachable")

            case .reachable(.ethernetOrWiFi):
                print("The network is reachable over the WiFi connection")

            case .reachable(.wwan):
                print("The network is reachable over the WWAN connection")

            }
        }

        // start listening
        reachabilityManager?.startListening()
   }
}

Start Network Reachability Observer

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        // add network reachability observer on app start
        NetworkManager.shared.startNetworkReachabilityObserver()

        return true
    }
}

回答2:

Here's my implementation. I use it in a singleton. Remember to hold on to the reachability manager reference.

let reachabilityManager = Alamofire.NetworkReachabilityManager(host: "www.apple.com")

func listenForReachability() {
    self.reachabilityManager?.listener = { status in
        print("Network Status Changed: \(status)")
        switch status {
        case .NotReachable:
            //Show error state
        case .Reachable(_), .Unknown:
            //Hide error state
        }
    }

    self.reachabilityManager?.startListening()
}

回答3:

I found the answer myself i.e by just writing a listener with closure as mentioned below:

let net = NetworkReachabilityManager()
net?.startListening()

net?.listener = { status in
    if net?.isReachable ?? false {

    switch status {

    case .reachable(.ethernetOrWiFi):
        print("The network is reachable over the WiFi connection")

    case .reachable(.wwan):
        print("The network is reachable over the WWAN connection")

    case .notReachable:
        print("The network is not reachable")

    case .unknown :
        print("It is unknown whether the network is reachable")

    }
}

回答4:

Using a singleton is working as I long as you keep a reference of reachabilityManager

class NetworkStatus {
static let sharedInstance = NetworkStatus()

private init() {}

let reachabilityManager = Alamofire.NetworkReachabilityManager(host: "www.apple.com")

func startNetworkReachabilityObserver() {
    reachabilityManager?.listener = { status in

        switch status {

        case .notReachable:
            print("The network is not reachable")

        case .unknown :
            print("It is unknown whether the network is reachable")

        case .reachable(.ethernetOrWiFi):
            print("The network is reachable over the WiFi connection")

        case .reachable(.wwan):
            print("The network is reachable over the WWAN connection")

        }
    }
    reachabilityManager?.startListening()
}

So you can use it like this anywhere in your app:

let networkStatus = NetworkStatus.sharedInstance

override func awakeFromNib() {
    super.awakeFromNib()
    networkStatus.startNetworkReachabilityObserver()
}

You will be notified of any change in your network status. Just for icing on the cake this is a very good animation to show on your internet connection loss.

回答5:

Apple says to use a struct instead of a class when you can. So here's my version of @rmooney and @Ammad 's answers, but using a struct instead of a class. Additionally, instead of using a method or function, I am using a computed property and I got that idea from this Medium post by @Abhimuralidharan. I'm just putting both the idea of using a struct instead of a class (so you don't have to have a singleton) and using a computed property instead of a method call together in one solution.

Here's the struct NetworkState:

import Foundation
import Alamofire

struct NetworkState {

    var isConnected: Bool {
        // isReachable checks for wwan, ethernet, and wifi, if
        // you only want 1 or 2 of these, the change the .isReachable
        // at the end to one of the other options.
        return NetworkReachabilityManager(host: www.apple.com)!.isReachable
    }
}

Here is how you use it in any of your code:

if NetworkState().isConnected {
    // do your is Connected stuff here
}